net: hns3: add handshake with VF for PF reset

Before PF asserting function reset, it should make sure
that all its VFs have been ready, otherwise, it will cause
some hardware errors.

So this patch adds function hclge_func_reset_sync_vf() to
synchronize VF before asserting PF function reset. For new
firmware which supports command HCLGE_OPC_QUERY_VF_RST_RDY,
we will try to query VFs' ready status within 30 seconds.
And keep the old implementation for compatible with firmware
which does not support this command.
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Reviewed-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_cmd.h

@@ -87,6 +87,7 @@ enum hclge_opcode_type {
 	HCLGE_OPC_QUERY_VF_RSRC		= 0x0024,
 	HCLGE_OPC_GET_CFG_PARAM		= 0x0025,
 	HCLGE_OPC_PF_RST_DONE		= 0x0026,
+	HCLGE_OPC_QUERY_VF_RST_RDY	= 0x0027,
 
 	HCLGE_OPC_STATS_64_BIT		= 0x0030,
 	HCLGE_OPC_STATS_32_BIT		= 0x0031,
@@ -588,6 +589,12 @@ struct hclge_config_mac_mode_cmd {
 	u8 rsv[20];
 };
 
+struct hclge_pf_rst_sync_cmd {
+#define HCLGE_PF_RST_ALL_VF_RDY_B	0
+	u8 all_vf_ready;
+	u8 rsv[23];
+};
+
 #define HCLGE_CFG_SPEED_S		0
 #define HCLGE_CFG_SPEED_M		GENMASK(5, 0)
 

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c

@@ -35,6 +35,9 @@
 #define BUF_RESERVE_PERCENT	90
 
 #define HCLGE_RESET_MAX_FAIL_CNT	5
+#define HCLGE_RESET_SYNC_TIME		100
+#define HCLGE_PF_RESET_SYNC_TIME	20
+#define HCLGE_PF_RESET_SYNC_CNT		1500
 
 /* Get DFX BD number offset */
 #define HCLGE_DFX_BIOS_BD_OFFSET        1
@@ -3184,6 +3187,39 @@ static int hclge_set_all_vf_rst(struct hclge_dev *hdev, bool reset)
 	return 0;
 }
 
+int hclge_func_reset_sync_vf(struct hclge_dev *hdev)
+{
+	struct hclge_pf_rst_sync_cmd *req;
+	struct hclge_desc desc;
+	int cnt = 0;
+	int ret;
+
+	req = (struct hclge_pf_rst_sync_cmd *)desc.data;
+	hclge_cmd_setup_basic_desc(&desc, HCLGE_OPC_QUERY_VF_RST_RDY, true);
+
+	do {
+		ret = hclge_cmd_send(&hdev->hw, &desc, 1);
+		/* for compatible with old firmware, wait
+		 * 100 ms for VF to stop IO
+		 */
+		if (ret == -EOPNOTSUPP) {
+			msleep(HCLGE_RESET_SYNC_TIME);
+			return 0;
+		} else if (ret) {
+			dev_err(&hdev->pdev->dev, "sync with VF fail %d!\n",
+				ret);
+			return ret;
+		} else if (req->all_vf_ready) {
+			return 0;
+		}
+		msleep(HCLGE_PF_RESET_SYNC_TIME);
+		hclge_cmd_reuse_desc(&desc, true);
+	} while (cnt++ < HCLGE_PF_RESET_SYNC_CNT);
+
+	dev_err(&hdev->pdev->dev, "sync with VF timeout!\n");
+	return -ETIME;
+}
+
 int hclge_func_reset_cmd(struct hclge_dev *hdev, int func_id)
 {
 	struct hclge_desc desc;
@@ -3350,17 +3386,18 @@ static void hclge_reset_handshake(struct hclge_dev *hdev, bool enable)
 
 static int hclge_reset_prepare_wait(struct hclge_dev *hdev)
 {
-#define HCLGE_RESET_SYNC_TIME 100
-
 	u32 reg_val;
 	int ret = 0;
 
 	switch (hdev->reset_type) {
 	case HNAE3_FUNC_RESET:
-		/* There is no mechanism for PF to know if VF has stopped IO
-		 * for now, just wait 100 ms for VF to stop IO
+		/* to confirm whether all running VF is ready
+		 * before request PF reset
 		 */
-		msleep(HCLGE_RESET_SYNC_TIME);
+		ret = hclge_func_reset_sync_vf(hdev);
+		if (ret)
+			return ret;
+
 		ret = hclge_func_reset_cmd(hdev, 0);
 		if (ret) {
 			dev_err(&hdev->pdev->dev,
@@ -3377,10 +3414,13 @@ static int hclge_reset_prepare_wait(struct hclge_dev *hdev)
 		hdev->rst_stats.pf_rst_cnt++;
 		break;
 	case HNAE3_FLR_RESET:
-		/* There is no mechanism for PF to know if VF has stopped IO
-		 * for now, just wait 100 ms for VF to stop IO
+		/* to confirm whether all running VF is ready
+		 * before request PF reset
 		 */
-		msleep(HCLGE_RESET_SYNC_TIME);
+		ret = hclge_func_reset_sync_vf(hdev);
+		if (ret)
+			return ret;
+
 		set_bit(HCLGE_STATE_CMD_DISABLE, &hdev->state);
 		set_bit(HNAE3_FLR_DOWN, &hdev->flr_state);
 		hdev->rst_stats.flr_rst_cnt++;